1. Field of the Invention
The present invention relates to a head protection air bag system comprising an air bag folded towards an upper edge side of a window on a side which faces an inner side of a vehicle for accommodation and adapted to be inflated completely by an inflation gas being caused to flow into an interior thereof so as to project downwards from the upper edge side of the window to thereby cover the side of the window which faces the inner side of the vehicle.
2. Related Art
In consideration of protection of occupants in a vehicle also when the vehicle overturns, it is preferable to cover as wide an area as possible on a side of a window which faces an inner side of the vehicle or an inner side of the window with an air bag which is completely inflated. As a conventional head protection air bag system, there was a head protection air bag system which was configured to include an inflatable shield portion for covering a side of a window facing an inner side of the vehicle or an inner side of a window when the air bag was inflated completely and an edge side shield portion disposed at a front edge side of the inflatable shield portion for accommodation in an area of a front pillar portion which extended obliquely downwards from an upper edge side of the window on a front edge side of the window, wherein an upper edge of the edge side shield portion which was inclined so as to match the inclination of the pillar portion was mounted on a body side member at the pillar portion at mounting portions provided in three locations along a front-rear direction (for example, refer to JP-A-2004-75038).
In the conventional head protection air bag system, however, since the air bag was folded to reduce a width dimension in a vertical direction with a lower edge side made to approach an upper edge side while forming folds along the front-rear direction, in a completely folded body which was made up by folding the air bag, the edge side shield portion was folded so as to be continued from the upper edge of the inflatable shield portion in a straight line along the front-rear direction, and an edge side folded portion formed by folding the edge side shield portion was accommodated in an interior of the pillar portion which was inclined relative to a horizontal direction. In other words, in the conventional head protection air bag system, since the mounting portions formed at the edge side shield portion were disposed in positions which were offset in the vertical direction with the air bag deployed flat, a straight-line distance which connected the mounting portions formed at the edge side shield portion became larger than a straight-line distance between the mounting portions at the edge side shield portion which results after the edge side shield portion had been folded, and in the air bag which had been inflated completely, a slag was generated in the upper location between the mounting portions at the edge side shield portion. Because of this, in the conventional head protection air bag system, even with the configuration in which the upper edge side of the edge side shield portion is mounted on the pillar portion side in the three locations along the front-rear direction, there had been room for improvement in covering the area on the window which lies on the lower side of the pillar portion with no open or uncovered spaces left.